A retrospective review of methotrexate‐induced hepatotoxicity among patients with psoriasis in a tertiary dermatology center in Malaysia

Background Methotrexate (MTX) is a common and efficacious systemic agent used for the treatment of moderate to severe psoriasis. Nevertheless, its use is associated with the risk of hepatotoxicity. This study was performed to study the association of MTX dose with regards to hepatotoxicity as evidenced by deranged transaminases. Methods This was a retrospective review of patients with psoriasis on MTX from 2000 to 2009 at the outpatient dermatology clinic, University Malaya Medical Centre (UMMC). We analyzed patients’ demography, serial laboratory investigations, liver ultrasounds, and liver biopsies of patients on MTX. Results Sixty‐six of 710 (9.30%) patients with psoriasis were prescribed MTX throughout the 10‐year period. Among them 57.6% developed deranged transaminases, with six requiring MTX withdrawal due to hepatotoxicity. The mean cumulative dose of MTX at the detection of liver enzyme derangement was 552.3 ± 596.1 mg. Conclusion A high proportion of patients on MTX had deranged transaminases. However, the number of serious events was low. We concluded from this study that the use of MTX is relatively safe in patients with moderate to severe psoriasis.